Method of lithographic printing



Nov. 17, 1925. 1,562,323

W. GRASS METHOD OF LITHOGRAPHIC PRINTING Original Filed Feb, 10, 1916 2 Sheets-Sheet 1 .Fl-Zgl.

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Nov. 17 1925- 3 W. GRASS METHOD OF LITHOQRAPHIC PRINTING Original'Filed Feb. 10, 1916 2 sheet-Sheet 2 4 b/& fig. Z

witness fl M 5% W70 g (WM al'lozucq Patented Nov. 17 1 925.

UNITED STATES PATENT OFFICE.

WILLIAM GRASS, OF WEEHAWKEN, NEW JERSEY, ASSIGNOR TO GRASS PATENTS COR- PORATIION, OF NEW YORK, N. Y.

NIETHOD OF LI'IHOGRAPHIG PRINTING.

Application filed February 10, 1916, Serial No. 77,489. Renewed March 11, 1922. Serial No. 543,090.

To all whom it may concern:

, Be it known that I, WILLIAM GRASS, a

subject of the Emperor of Germany, residing at Weehawken, in the county of Hud- 5 son and State of New Jersey, have invented certain new and useful Improvements in Methods of Lithographic Printing, of which the following is a specification.

The invention relates to a method of lithographic offset printing in which the printing surface is prepared and used in a new and improved way, without the -intervention of any individual type or linotype from which an impression is required to be taken in the usual manner.

The invention has for its objects to simplify and improve the printing process, and ob tain better results in the distinctness of the printing and in the durability of the devices used, especially of the printing surface and of the master transparency or translucency in which the text or other composition is permanently embodied in a form very convenient for preservation and for reproduction at any time that reprinting is desired.

With such objects in view, as well as other advantages which maybe incident to the use of the improvements, the invention consists in. the procedure, hereinafter set forth and claimed, with the understanding that the several necessary elementsfconstituting the same may be varied in proportions and arrangement without departing from the nature of the invention.

In order to make the invention more clearly understood there are shown in the accompanying drawings means for carrying the same into practical effect, without limiting the improvements, in their useful applications to the particular constructions which,

for the purpose of explanation, have been made the subject of-illustration. In the said drawings Fig. 1 is a frontjview of a portion of the apparatus, comprising aframe or easel in or on which movable type to be photographed are assembled. 4

Fig. 2 is a side view of the same, illustrating also a camera for photographing the matter on said easel and showinga hand crank for more readily moving said easel.

7 Fig. 3is a horizontal sectionof said easel on line IIIIII said crank. l

sharply of Fig. 1 and adding also Fig. 5 is a plan View of the master transparency.

Fig. 6 is a section view on line VI-VI of Fig. 5, the same being in the form of an illustrative diagram.

Fig. 7 is an end view of a lithographic cylinder, having a lithographic grained surface of zinc or its equivalent, and having applied thereto the said master transparency.

Fig. 8 is an elevation of the said cylinder having the composition or design to be printed formed in in'taglio thereon, in or slightly below the lithographic grain of thesurface.

Fig. 9 is a vertical sectional View of a portion of the easel, enlarged, with a movable letter or type suspended thereon.

Fig. 10 is a view of a piece of the stripping film.

Fig. 11 is a similar view of the stripping dry plate.

Fig. 12 is a sectional view, greatly magnified, showing conventionally a portion of the printing surface or plate.

A indicates an easel or equivalent support, in or on which movable letters or type 1 are to be assembled for the production of text to be printed. Preferably the type support- 4), so as to be capable of being clearly photog'raphed', the bases 2 of the individual type around the surfaces of the letters and the entire background of the easel being "black The said type are characterized by having 1 their faces white or light-reflecting (Fig.

or non-reflecting, so that a photograph of,-

the entire composition on the easel"will show on the photographic plate or film which is used in the camera. The said camera is shown at B, and is preferably maintained in a constant position a suitable distance from and focused on the face of the set up it may be rapidly photographed.

The faces of the letters on the type are of what may be termed direct reading formation (not reverse reading as in the case of type from which a physical impression is taken) and the composition may be easily read in the ordinary way. Proof reading and correction may continue by a proof readeroperating on the type that have been set, while the compositor is still setting up the type at the lower part of the easel. The type will be contained in cases suitably situated at or near the easel within convenient reach, or the type may be assembled mechanically by a linotype apparatus or its equivalent; the present invention however not being confined to any particular means for assembling the type on the easel, and that part of the invention not requiring to be further illustrated herein.

In that .form of easel which has been illus trated the type carrying portion consists of an endless carrier comprising belts or chains 3 which run upon pulleys rollers, or sprockets 4. The pulleys or roller at the top part of the easel are fixed or mounted on a shaft 5, and those at the bottom of the easel on a shaft 6. A step by step, or line by line, upwardmovement of the front surface of the easel is produced by hand or by any suitable mechanism for the purpose. On the said chains are mounted horizontal slats or flights 7 which are capable of having the movable type easily and rapidly applied thereto as the setting of the composition to be printed proceeds. The bases 2 of the letters may be provided with hooks 8 adapted to hook over the top edges of the slats (Fig. 9). As the letters pass over the shaft 5 and to the back of the eas'el they may be automatically discharged by gravity, for distributing into their cases.

The said easel has a surface, on which the arranged type are received as aforesaid, of

' suitable dimensions to be conveniently focused on a movable film 9 in'the cameraB. As soon as the composition has been completed in type, which may conveniently be a column or a portion of a column of a newspaper, an exposure is made of the film in the camera, the latter being permanently arranged in proper focus relative to the easel,

' so that no time is lost in making such expo;-

sure. The film is then developed-and dried.

The film is supplied for eaclf exposure by unwinding from a reel 10, and passes from the camera into a developing trough 11. Until it is developed the film 9 is protected from light except when exposed in the camera. As the subjectexposed has white or light-reflecting surfaces against a black or rion-reflecting background, no particular care is necessary in the said development of the arrangement bein black and white negative. It may be here stated that the above described apparatus is capable of producing very clear and perfect- .ly formed letters on the film, the type of white letters which are photographed being several times larger than ordinary type, and of perfect formation; the result being that the film shows letters reduced to the ordinary size desired in a newspaper, but of very -perfect formation, distinctness, and

alinement. I

The film is a contrast stripping film, the emulsion-film face 12 of which can be stripped from the celluloid or equivalent back 13, when the film has been dried, without impairing the integrity of such stripped" film (Fig. 10). The latter is then caused to adhere to the surface of a transparent or translucent tissue-paper 14 (Fig. 5), which may be such as is employed in -lithog raphy'.v This paper has a varnished surface composed of linseed oil and resin.

A paper known as photo-phane is suitable for the purpose.

The above described process of arranging the type and photographing, is continued until sufficient finished film is produced to make a page of a paper. -The said columns, or portions of columns, of film are arranged as desired to make up the saidpage; and

lens, and through a screen in the camera on to" a cont'iast, stripping dry plate in the camera, on which the picture is produced in dot form. The plate is then developed and dried in the usual photographic way. When dry, the film 15 containing this picture is cut around with a knife and stripped from its plate (Fig. 11) and stuck on said printed transparency 14 at the desired place in a column, or across two -or-more columns, its

direct reading and corresponding with t e text. A half-tone picture or cut, printed on translucent paper,

may be applied on the transparencywhere desired. The arrangement of the. .film or parts of. film on the transparentsheet being complete, asimilar sheet 16 is preliminarily stretched, slightly moistened, as .by steaming, and applied onthe firstsheet let of, the transparent paper," and rolled down thereon, so that the two transparent sheets form in efi'ect a single sheet with all of the sections of film 12, 15 held in placebetween film, it only being necessary to get a good them. This complete sheet may be termed nceaeae a master transparency, and may be used at any time for the production of a lithographic printing plate, and may be indefinitely preserved for the purpose of reprinting at any future time. Before it is put awa both of its outside surfaces are rendere non-adhesive by rubbing thereon French chalk or talcum.

Proceeding at this stage of the process with the production of the printing surface, a zinc or aluminum plate 17 having a grained lithographic surface 18 is coated on said surface with a sensitive film 19 (Fig. 7) of fish glue or the equivalent. This film being dry, and having been protected from light, the plate is placed in a printing frame with said prepared transparency 14, 16 back down thereon and is exposed to light, or the transparency may be stuck on as hereafter mentioned. For direct instead of offset printing the transparency would be applied face down on the plate. After said exposure the plate is developed and the unexposed and .unhardened parts of the film, which have been protected by the opaque lines or dots of the transparency, are washed or dissolved away by water or the equivalent. The letters are white on the easel, black on the film 12, and spaces representing them are left in the film 19 by said washing. The plate with its remaining hardened film parts is then washed and dried. Preferably before said washing the.

plateis dyed to make the design clearly 7 visible and enable it to be ascertained whether the design is perfect before proceeding further. The plate 17 is then etched in ferric chloride solution, of preferably about 38 to 43 Baum, for about two or three minutes, at normal temperature, thereby removing said grain 18 down to the solid part of the plate, and forming in relatively shallow intaglio 20 the lines and dots which are to be printed. The plate is then washed and dipped in a weak hydr vchloride oath for about half a minute, to soften the film. Then the hydrochloric solution is washed off and the plateis dried. Lithographic transfer ink or grease 21 (Fig. 12) is then applied or rubbed into the intagfio recesses, and preferably a celluloid or simi-' lar varnish 28 is also applied, before, with or after the ink. The application of any material in the intaglio, which makes it receptive of ink, will serve the purpose. The plate is then washed in water and rubbed, as with wool or 'telt, till all film is removed. The plate is dried and powdered with resin, and the excess of resin is dusted off, and the plate is cleaned and given a surface etch with a solution suitable, according to the material of which the plate is made, to render the normal high parts or parts other than the intaglio, non-receptive of ink when properly damped. The plate is then cleaned or sponged off with water, and gummed with a (thin solution to prevent oxidation and protect the surface of the plate.

The plate is then put in the printing press, in flat form or around a cylinder, the latter for continuous rotary printing.

The intaglio is very shallow. For instance, a plate of about 28/1000 gauge can be repeatedly used, the former designs being etched ofi', by etching away the high parts by a process analogous to that already described. Tn both etching processes the back of the plate is or may be protected by a suitable resisting coating. Or the old designs can be removed in any other suitable way.

When the intaglio is to be used in cylindrical form, suitable for a rotary newspaper lithographic oflset printing machine, the procedure is as follows: The zinc or aluminum plate is or may be roduced in the form of a seamless tube 22, w iich is attached concentrically on a mandrel 23. This plate is evenly coated with a photographic film of fish glue such as 'is above described, or its equivalent, and the transparency 14, 16is stuck on it, by an adhesive containing no water, Fig. 7 and exposed to light by rotating the cylinder in front of an arc lamp. The transparency is then stripped from the cylinder and the latter is treated and etched as already described. The adhesive is removed trom the back of the transparency by rubbing with benzine; talcum or French chalk is then rubbed on both faces of the transparency and it is laid away'until it is required for the preparation of another plate.

A relatively coarse and sharp grain on the in the invention described without any consequent roughening of the lines or dots of the design, as would be the case it such grain were used on a planagraphic plate. The etching herein described as producing an intaglio may also be described as removing the said water-receiving grain, so that the lithographic ink is received wherever-the grain has been removed, and its extent is defined and maintained without spreading (so that uniform impressions are produced) by the walls of the remaining grain wh1ch surround the places from which thegrain has been removed. Less particularity is necessary as to the exact degree of damping, and also as to the quality of the ink, which need not be expensive in order to obtain methods of producing the suitable printing surface may be employed, and the invention does not exclude the use of a planograph printing plate, although the latter will not give such perfect results and will not be so" durable.

,It will be understood that the invention may be employed in a process involving the use of two offsetting cylinders simultane ously printing opposite to each other on the opposite sides of a Web of paper.

What is claimed is:

1. A process of lithographic printing for newspapers and other purposes, in which a lithographic metal plate is produced by photographing light-reflecting I directly reading and individually set up letters having a non-reflecting background, and from the negative so made printing on the plate, and causing said plate to have a normal high ink rejecting surface and surfaces at a slightly lower level, said lower surfaces constituting the design or matter to be printed.

2. A process of lithographic printing for newspapers and other purposes, in which a lithographic metal intaglio plate is produced by photographing light-ref1ecting letters having a non-reflecting background, moving the said letters, while properly set up, progressively during intervals of photographing and from the negative so made printing on the plate, and causing saidplate to have a normal high ink rejecting surface and surfaces at a lower level, said lower surfaces constituting the design or matter to be printed.

3. A process of lithographic printing for newspapers and other purposes, in which a lithographic metal- ,intaglio plate is produced by assembling individual type and photographing the same, and from the negative so made printing on the plate, and causing said plate to have a normal high ink rejecting surface and surfaces at a slightly lower level, said lower surfaces constituting the design or matter to be printed.

4. A process of lithographic printing for newspapers and other purposes, in which a lithographic metal intaglio plate is produced by photographin light-reflecting letters havin a non-re ectnng background, and from t e negative so made printing on the plate by vthe aid of films carried-by a transparency, and causing said plate to have a normal high ink rejecting surface and surfacesoat a slightly lower level, said lower surfaces constituting the design or matter to be printed.

5. The herein described process of newspaapfr and other printing, which consists in ing a photographic negative direct-1y from arranged letters, on which negative the letters are light-intercepting on a translucent film or plate; photographing from said negative on a lithographic plate having making a photogra hic negative film di-- rectly from arrange letters, on which negative the letters are light-intercepting on the translucent film; applying said film on a transparency, and applying with such textfilm other film which is a photographic negative of pictorial matter; photographing from said transparency on a litho-' graphicjplate having a sensitized film on a grained surface; and treating and etching said plate.

7. The herein described process of newspaper and other printing, which consists in assembling letters having direct reading white or light-reflecting faces on a nonrefiecting background; moving said type as they are assembled to a photographing position; proof-reading and correcting saidletters if necessary; photographing an assembled body of said letters on a sensitized film carried by a base film; developing the exposed film; stripping the developed film from said base film; causing said stripped film to adhere on a translucent material; causing another sheet of such translucent material to adhere over said film; printing by light through said composite translucent sheet on to a lithographic plate having a sensitized film on its grained lithographic surface; removing the unexposed and unhardened portions of the plate film from said plate; and etching said plate to produce the letters thereon in intaglio.

8. In newspaper and other printing the process of preparing a photographic negative of matter to be printed, which consists in assembling photographable types successively end to end to produce lines, and guiding the type into position along lines parallel with their faces; making a photographic negative of the textso produced, then moving said text as a whole and causing the photographic field to be occupied by 'a subsequent portion of said text assembled as above described, and then making another negative of such subsequent portion of text, and sosuccessively and progressively producmg the required negatives.

newspaper and other printing the 7 typ photographic field to be occupied by a subsequent portion of said text assembled as above described, and then making another negative of such subsequent portion of text, and so successively and progressively producing the required negatives, and distributing the type successively as they pass out of the photographic field.-

10. The herein described process which consists in assembling photographable type to produce a series of lines of said type, and successively moving suitable numbers of said lines of type into the photographic field, and producing successive photographic negatives of said type, and treating lithographic surfaces with the aid of said negatives for the production 'of lithographic printing surfaces representing all of said 11. The herein described process which consists in assembling photograph-able type to produce a series of lines of said type, and successively moving suitable numbers of said lines of type into the photographic field, and producing successive photographic negatives of said type, and treating lithographic surfaces with the aid of said negatives for the production of lithographic printing surfaces representing all of said type, and distributing said'type as they pass out of the photographic field.

12. A process of lithographic printing for newspapers and other purposes, in which a lithographic metal plate is produced by photographing light-reflecting designs having a non-reflecting background, and from the negative so made printing on the plate,

and causing said plate to have a normal A high ink-rejecting surface and having surfaces at a slightly lower level, said lower surfaces constituting the design or matter to be printed.

In testimony whereof I aflix my signature.

\VILLIAM GRASS. 

